Hundreds of demonstrators, condemning Israel's blockade of the Gaza Strip, picketed at the Port of Oakland on Sunday and may have prevented an Israeli cargo ship from unloading for the day.

Two shifts of longshoremen agreed not to cross the picket line, leaving nobody to unload the vessel.

"Our objective was to boycott this ship for 24 hours, and we succeeded in doing that," said Richard Becker, with the ANSWER Coalition, one of the groups that organized the protest.

The demonstrators first gathered before dawn at Berth 58, where a ship from Israel's Zim shipping line was scheduled to dock Sunday, first in the morning then in the afternoon, protesters said. It eventually arrived around 6 p.m., Becker said, but by that time the dockworkers had agreed not to show up to unload the vessel.

An Israeli Consulate representative disputed that account, saying the ship was always scheduled to arrive about 6 p.m.

International pressure to end the Gaza closure has increased since Israeli commandos stormed a flotilla of ships attempting to run the blockade on May 31, killing nine people.

Israel formally announced on Sunday it would ease its blockade of Gaza, allowing more goods to enter the impoverished area. Israel said it would expand operations at the land crossings already operating to enable processing of "a significantly greater volume of goods" and "the expansion of economic activity."

More than 500 people showed up about 5:30 a.m. Sunday to begin the protest, according to police estimates. By around 10 a.m. the crowd dispersed, but about 200 protesters returned in the afternoon when the second shift of dockworkers were scheduled to work.

Becker said some workers showed up for the morning shift, but virtually none did for the second. All agreed not to unload the ship or cross the picket lines, citing concern for their personal safety.

"I want the Palestinian people to have peace and land. They have been suffering for 60 years, and it's time for them to have justice," said Marina Gutierrez of Kensington, a demonstrator who showed up both in the morning and the afternoon.

In the afternoon, two Israel supporters stood across the street from the pro-Palestinian demonstrators waving Israeli and American flags.

"Israel is a democracy, just like America, and Israel is faced with a fight for its life," said Faith Metzer of El Cerrito.